European Journal of Organic Chemistry

Cover image for Vol. 2014 Issue 12

Early View (Online Version of Record published before inclusion in an issue)

Editor: Haymo Ross, Deputy Editor: Susan Wilkinson

Impact Factor: 3.344

ISI Journal Citation Reports © Ranking: 2012: 14/57 (Chemistry Organic)

Online ISSN: 1099-0690

Associated Title(s): Advanced Synthesis & Catalysis, Asian Journal of Organic Chemistry

VIEW

  1. 1 - 100
  1. Full Papers

    1. Organocatalysis

      Diterpenoid Alkaloid Lappaconine Derivative Catalyzed Asymmetric α-Hydroxylation of β-Dicarbonyl Compounds with Hydrogen Peroxide

      Zhi Li, Mingming Lian, Fan Yang, Qingwei Meng and Zhanxian Gao

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402019

      Thumbnail image of graphical abstract

      Ten new organocatalysts derived from the diterpenoid alkaloid lappaconitine are described. Activities for the enantioselective α-hydroxylation of β-dicarbonyl compounds with 30 % hydrogen peroxide as a green and practical source of oxygen is described. This protocol allows convenient access to the corresponding α-hydroxy-β-dicarbonyl compounds with up to 98 % yield and 92 % ee under mild conditions.

    2. Ruthenium Carbenoid

      Regioselective Synthesis of Highly Functionalized Furans Through the RuII-Catalyzed [3+2] Cycloaddition of Diazodi­carb­onyl Compounds

      Likai Xia and Yong Rok Lee

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402067

      Thumbnail image of graphical abstract

      A novel method for the regioselective synthesis of highly functionalized furans has been developed through RuII-catalyzed cascade reactions of readily available cyclic and acyclic diazodicarbonyl compounds with terminal alkynes. The synthesis has several desirable features, such as mild conditions, high regioselectivity, a concise one-pot protocol, short reaction time, and easy purification.

    3. Natural Product Synthesis

      Biogenetically Inspired Total Synthesis of (+)-Liphagal: A Potent and Selective Phosphoinositide 3-Kinase α (PI3Kα) Inhibitor from the Marine Sponge Aka coralliphaga

      Takaaki Kamishima, Takuya Kikuchi, Koichi Narita and Tadashi Katoh

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402082

      Thumbnail image of graphical abstract

      (+)-Liphgal, a biologically attractive and structurally unique marine natural product, was synthesized in 29 % overall yield in a longest liner sequence of 13 steps from commercially available (+)-sclareolide. A characteristic tetracyclic core structure was established by a method based on the proposed biosynthetic pathway.

    4. Heterocyclic Synthesis

      Straightforward Access to Hexahydropyrrolo[2,3-b]indole Core by a Regioselective C3-Azo Coupling Reaction of Arenediazonium Compounds with Tryptamines

      David E. Stephens and Oleg V. Larionov

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402088

      Thumbnail image of graphical abstract

      A new method for construction of the pyrroloindoline framework by way of arenediazonium-triggered cyclization of tryptamines allows for direct and efficient access to a synthetically important structural motif. The reaction is the first example of diazonium-induced 1,2-diamination.

    5. Host–Guest Chemistry

      Resorcin[4]arene-Based Molecular Baskets and Water-Soluble Container Molecules: Synthesis and 1H NMR Host–Guest Complexation Studies

      Daniel Fankhauser, Dušan Kolarski, Wolfram R. Grüning and François Diederich

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402140

      Thumbnail image of graphical abstract

      1H NMR binding studies of novel resorcin[4]arene-based molecular baskets and water-soluble container molecules have been performed with small molecular guests. Sequences of complexation strength for structurally similar heteroalicyclic guests differ in organic and aqueous media. Guest inclusion rigidifies the water-soluble hosts and rotation of the capping bridge slows, revealing planar chirality.

  2. Short Communications

    1. C–N Coupling

      Solvent-Free Buchwald–Hartwig Reaction of Aryl and Heteroaryl Halides with Secondary Amines

      Maxim A. Topchiy, Andrey F. Asachenko and Mikhail S. Nechaev

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402077

      Thumbnail image of graphical abstract

      Disubstituted amines are efficiently coupled with aryl and heteroaryl halides through Buchwald–Hartwig amination under solvent-free aerobic conditions. The reaction is catalyzed by a Pd(OAc)2/RuPhos system in air. Various (hetero)aryl halides are coupled with diaryl, alkyl–aryl, and dialkylamines in good to excellent yields.

    2. Arylation

      Palladium-Catalyzed Direct Arylation of Polyfluoroarenes with Organosilicon Reagents

      Huixin Fan, Yaping Shang and Weiping Su

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402091

      Thumbnail image of graphical abstract

      Palladium-catalyzed intermolecular C–H bond arylation between polyfluoroarenes and organosilicon reagents is developed for the synthesis of polyfluorobiarenes. This method is simple and compatible with a broad range of functional groups and furnishes the corresponding products.

    3. Vitamin E Synthesis

      Total Synthesis of (2RS)-α-Tocopherol through Ni-Catalyzed 1,4-Addition to a Chromenone Intermediate

      Andreas Ole Termath, Janna Velder, René T. Stemmler, Thomas Netscher, Werner Bonrath and Hans-Günther Schmalz

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201402240

      Thumbnail image of graphical abstract

      The total synthesis of 2-ambo-α-tocopherol is elaborated starting from trimethylhydroquinone and (R,R)-hexahydrofarnesol. In the key step, the quaternary center is established through Ni-catalyzed 1,4-addition of AlMe3 to a chromenone intermediate This transformation, which likely proceeds through a radical mechanism, cannot be rendered stereoselective by means of chiral ligands.

  3. Full Papers

    1. Aminocyclitols and CuAAC

      Synthesis of 1,2,3-Triazoles from Azide-Derivatised Aminocyclitols by Catalytic Diazo Transfer and CuAAC Click Chemistry

      Li Ji, Guo-Quan Zhou, Chao Qian and Xin-Zhi Chen

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201301874

      Thumbnail image of graphical abstract

      Aminocyclitol derivatives of 1,2,3-triazoles were synthesised by CuII-catalysed diazo transfer, with use of imidazole-1-sulfonyl azide hydrochloride as a cheap, shelf-stable diazo transfer reagent, and smooth CuAAC between the azidocyclitols and various terminal alkynes under Meldal's conditions. Stereochemistry was confirmed by 2D-NMR. Safer, more efficient one-pot procedures were also developed.

    2. Iron-Catalyzed Cyclization

      Iron-Catalyzed Oxidative 1,2-Carboacylation of Activated Alkenes with Alcohols: A Tandem Route to 3-(2-Oxoethyl)indolin-2-ones

      Xuan-Hui Ouyang, Ren-Jie Song and Jin-Heng Li

      Article first published online: 17 APR 2014 | DOI: 10.1002/ejoc.201400043

      Thumbnail image of graphical abstract

      A route to 3-(2-oxoethyl)indolin-2-ones is presented that involves iron-catalyzed oxidative tandem reaction of N-arylacrylamides with alcohols. This method represents a new 1,2-difunctionalization of activated alkenes with alcohols, and provides a shortcut to carbonyl-containing oxindoles from alcohols.

  4. Short Communications

    1. Isomerization

      Ruthenium-Catalyzed One-Pot Synthesis of (E)-(2-Arylvinyl)boronates through an Isomerization/Cross-Metathesis Sequence from Allyl-Substituted Aromatics

      Rémy Hemelaere, Frédéric Caijo, Marc Mauduit, François Carreaux and Bertrand Carboni

      Article first published online: 15 APR 2014 | DOI: 10.1002/ejoc.201402192

      Thumbnail image of graphical abstract

      A new stereoselective route to (E)-alkenylboronates starting from the isomerization of allyl-substituted aromatics is developed. This simple process catalyzed by a modified Hoveyda–Grubbs catalyst is based on an isomerization/cross-metathesis sequence that is compatible with a large variety of allylbenzene derivatives.

    2. Double Reduction

      Catalyst-Free One-Pot Tandem Reduction of Oxo and Ene/Yne Functionalities by Hydrazine: Synthesis of Substituted Oxindoles from Isatins

      Mukund Jha, Ganesh M. Shelke and Anil Kumar

      Article first published online: 15 APR 2014 | DOI: 10.1002/ejoc.201402038

      Thumbnail image of graphical abstract

      An unprecedented hydrazine-mediated tandem reduction of oxo and N-ene/yne functionalities of substituted isatins is reported to access various oxindoles. The reaction is performed by treating N-(2-alkenyl)/propargylisatins with hydrazine hydrate under catalyst-free refluxing conditions. The reduction proceeds efficiently without the aid of any catalyst at ambient pressure.

    3. Cross-Coupling

      Palladium-Catalyzed Suzuki Cross-Coupling of Phenylhydrazine or (Phenylsulfonyl)hydrazine

      Yahui Li, Wei Liu, Qingshan Tian, Qing Yang and Chunxiang Kuang

      Article first published online: 15 APR 2014 | DOI: 10.1002/ejoc.201400126

      Thumbnail image of graphical abstract

      The palladium-catalyzed Suzuki cross-coupling of phenylhydrazine or (phenylsulfonyl)hydrazine was developed for the preparation of biaryl compounds in high yields. These hydrazines can also be used in other cross-coupling reactions. A possible pathway of this reaction is discussed.

  5. Full Papers

    1. Ligand Synthesis

      Regioselective Biomimetic Oxidative Cyclization Strategy for the Synthesis of Aryldihydronaphthalene Lignans

      Wenling Li, Hao Liu, Jingyan Xu, Peng Zang, Qian Liu and Wenbo Li

      Article first published online: 15 APR 2014 | DOI: 10.1002/ejoc.201301825

      Thumbnail image of graphical abstract

      The natural aryldihydronaphthalene lignans 8-8-cyclic diferulic acid and canabisin D have been concisely synthesized in four and five steps, respectively, from ethyl 5-tert-butylferulate by using a regioselective biomimetic oxidative cyclization strategy.

    2. Ring-Closing Metathesis

      Stereocontrolled Synthesis of a C1–C10 Building Block (“Southwestern Moiety”) for the Unnatural Enantiomers of the Polyene Polyol Antibiotics Filipin III and Pentamycin: A Sultone-Forming Ring-Closing Metathesis for Protection of Homoallylic Alcohols

      Patrick Walleser and Reinhard Brückner

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201400145

      Thumbnail image of graphical abstract

      The twofold ring-closing metathesis of homoallyl crotonate and homoallyl ethenesulfonate intermediate A gave unsaturated lactone and sultone containing intermediate B. The lactone was modified by diastereoselective 1,4-addition of a silyl cuprate and the sultone was removed to deliver a homoallylic alcohol that iodocarbonatized cis-selectively (→ C). A diastereoselective aldolization followed (→ → D).

  6. Short Communications

    1. Stereoselective Access to β-C-Glycosamines by Nitro-Michael Addition of Organolithium Reagents

      Thierry Delaunay, Thomas Poisson, Philippe Jubault and Xavier Pannecoucke

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201402001

      Thumbnail image of graphical abstract

      The nitro-Michael addition of organolithium reagents to 2-nitroglycal derivatives is reported. This methodology affords straightforward and stereoselective access to C-nitroglycosides, which are obtained in good to excellent yields with up to 100:0 diastereoisomeric ratio.

  7. Full Papers

    1. Sugar Triphosphates

      Synthesis of Pyranonucleoside-6′-triphosphates through the cycloSal-Method

      Johanna Huchting and Chris Meier

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201402047

      Thumbnail image of graphical abstract

      The synthesis of sugar triphosphates is often low yielding owing to low conversion and difficult purification. For the synthesis of pyranonucleoside-6′-triphosphates, cycloSal activated pyranonucleoside-phosphates were prepared. These were efficiently converted into triphosphates by a “titration-like” reaction. The use of only a slight excess of pyrophosphate facilitated purification significantly. The triphosphates were isolated in yields of 63–72 %.

    2. Heterocycles

      Synthesis of 1-(1H-Tetrazol-5-yl)-2H-isoindole Derivatives through Ugi Four-Component and Silver-Catalyzed Reactions

      Ran Wu, Shang Gao, Xu Chen, Guanghui Yang, Lingling Pan, Gaobo Hu, Ping Jia, Weihui Zhong and Chuanming Yu

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201402098

      Thumbnail image of graphical abstract

      A one-pot, two-step synthesis of 1-(1H-tetrazol-5-yl)-2H-isoindole derivatives through Ugi four-component reaction/AgNO3-catalyzed reaction of 2-alkynylbenzaldehydes, amines, isonitriles, and Me3SiN3 has been developed. The transformation proceeds through 5-exo-dig cyclization, [1,3]-H shift, and [1,5]-H shift to generate the products in moderate to excellent yields.

  8. Short Communications

    1. Gold Catalysis

      Gold-Catalyzed 5-endo-dig Cyclization of 2-[(2-Aminophenyl)ethynyl]phenylamine with Ketones for the Synthesis of Spiroindolone and Indolo[3,2-c]quinolone Scaffolds

      Basi. V. Subba Reddy, Manisha Swain, S. Madhusudana Reddy, J. S. Yadav and B. Sridhar

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201402006

      Thumbnail image of graphical abstract

      A gold-catalyzed 5-endo-dig/spirocyclization of 2-[(2-aminophenyl)ethynyl]phenylamine with isatins and ketones is achieved for the synthesis of spiroindolone and indolo[3,2-c]quinolone scaffolds in good yields with high regioselectivity under mild conditions.

  9. Full Papers

    1. Cross-Coupling

      Ligand-Free Ullmann-Type C–Heteroatom Couplings Under Practical Conditions

      Imma Güell and Xavi Ribas

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201400033

      Thumbnail image of graphical abstract

      We describe a new easy-to-use method for the ligand-free copper-catalyzed arylation of amides, alcohols, and amines that affords good cross-coupling product yields for a wide range of substrates (bromobenzene and iodobenzene derivatives) and nucleophiles.

    2. Spiro Compounds

      Sulfoximine-Based Modular Enantioselective Synthesis of Azaspirocycles Featuring Sulfoximine Displacement, Dianion Cycloalkylation, RCM and N-Acyliminium Ion Formation

      Adeline Köhler (née Adrien), Gerhard Raabe, Jan Runsink, Franz Köhler and Hans-Joachim Gais

      Article first published online: 14 APR 2014 | DOI: 10.1002/ejoc.201400068

      Thumbnail image of graphical abstract

      A modular, enantioselective synthesis of azaspirocycles was devised based on the special features of sulfoximines, including chirality, carbanion stabilization, nucleofugacity, and nucleophilicity. Key steps are intramolecular amination, C,N-dianion cycloalkylation, sulfoximine displacement, N-acyliminium ion formation, and ring-closing metathesis.

  10. Short Communications

    1. Natural Products

      A Three-Step Synthesis of the Guaianolide Ring System

      Jan Hullaert, Duchan R. Laplace and Johan M. Winne

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201402170

      Thumbnail image of graphical abstract

      The guaianolide ring system, a naturally abundant tricyclic sesquiterpenoid scaffold, is assembled in just three straightforward synthetic operations by using a highly diastereoselective intramolecular (4+3) cycloaddition reaction of a catalytically generated furfuryl cation intermediate.

  11. Full Papers

    1. C–H Activation

      2,4- and 2,5-Disubstituted Arylthiazoles: Rapid Synthesis by C–H Coupling and Biological Evaluation

      Lilia Lohrey, Takahiro N. Uehara, Satoshi Tani, Junichiro Yamaguchi, Hans-Ulrich Humpf and Kenichiro Itami

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201402129

      Thumbnail image of graphical abstract

      We have established a step-economical and diversity-oriented synthesis of 2-arylidenehydrazinyl-4-arylthiazoles and 2-arylidenehydrazinyl-5-arylthiazoles that utilizes C-4- and C-5-selective C–H coupling methodologies. A rapidly created library of 54 new 2-arylidenehydrazinyl-4-arylthiazole and 2-arylidenehydrazinyl-5-arylthiazole analogues were tested extensively for their biological activity.

  12. Microreviews

    1. Fluorinated Sulfoximines

      Fluorinated Sulfoximines: Preparation, Reactions and Applications

      Xiao Shen and Jinbo Hu

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201402086

      Thumbnail image of graphical abstract

      During the last forty years, particularly in the past decade, fluorinated sulfoximines have attracted much attention and experienced rapid research progress in organic synthesis and materials- and life-science-related fields. In this microreview we summarize the preparation, reactions and applications of fluorinated sulfoximines (mainly α-fluoro sulfoximines).

  13. Full Papers

    1. β-Ketoenamide Synthesis

      One-Pot Stereoselective Synthesis of (Z)-β-Ketoenamides from β-Halo α,β-Unsaturated Aldehydes

      Junali Gogoi, Pranjal Gogoi and Romesh C. Boruah

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201400007

      Thumbnail image of graphical abstract

      A simple and cost effective method has been developed for the synthesis of steroidal and non-steroidal β-ketoenamides from their corresponding β-halo α,β-unsaturated aldehydes. This protocol provides a stereoselective access to (Z)-β-ketoenamides; product structures were validated by single crystal X-ray diffraction (XRD) studies.

    2. Natural Product Synthesis

      Domino Recombinant γ-Isomerization and Reverse Wacker Oxidation of γ-Vinyl-γ-butyrolactone: Synthesis of (+)-trans-, (–)- and (+)-Disparlures

      Venkati Bethi, Pullaiah Kattanguru and Rodney A. Fernandes

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201400021

      Thumbnail image of graphical abstract

      A palladium-catalyzed domino recombinant γ-isomerization and reverse Wacker oxidation of γ-vinyl-γ-butyrolactone has been explored. The building blocks synthesized therein were successfully transformed into (+)-trans-disparlure and (–)- and (+)-disparlure with overall yields of 19.3, 20.7 and 22.6 %, respectively.

    3. Aromatization

      Copper(II)-Catalyzed Aromatization Followed by Bromination of Cyclohexenones Leading to Phenols and Bromophenols

      Hung-Chun Tong, K. Rajender Reddy and Shiuh-Tzung Liu

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201400158

      Thumbnail image of graphical abstract

      Conversion of substituted cyclohexenones into corresponding phenols and/or bromophenols can be achieved using copper acetate as the catalyst in the presence of LiBr and CF3COOH under oxygen.

    4. Spirocyclization

      Gold(I)-, Palladium(II)-, Platinum(II)-, and Mercury(II)-Catalysed Spirocyclization of 1,3-Enynediols: Reaction Scope

      Alexander Zhdanko and Martin E. Maier

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201402029

      Thumbnail image of graphical abstract

      Spirocyclization of different 1,3-enynediols provides [5,6]-spiroacetals in high yield. The reaction is catalysed by various gold(I), palladium(II), platinum(II), and mercury(II) catalysts. In particular, the successful application of a new cationic palladium pincer complex for electrophilic activation of alkynes has been demonstrated.

  14. Microreviews

    1. Organic Salts

      Di- and Tricationic Organic Salts: An Overview of Their Properties and Applications

      Francesca D'Anna and Renato Noto

      Article first published online: 11 APR 2014 | DOI: 10.1002/ejoc.201301871

      Thumbnail image of graphical abstract

      Di- and tricationic organic salts combine the properties of corresponding monocationic salts with individual features due to the presence of different charged heads on the cation structures. This allows their use in different fields of application such as ionic liquid crystals and gel phases.

  15. Full Papers

    1. Dendritic Molecules

      Arylethynyl-Substituted Tristriazolotriazines: Synthesis, Optical Properties, and Thermotropic Behavior

      Stefan Glang, Thorsten Rieth, Dorothee Borchmann, Ilaria Fortunati, Raffaella Signorini and Heiner Detert

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201400088

      Thumbnail image of graphical abstract

      Star-shaped and dendritic molecules with a triphenyl-tristriazolotriazine core and flexible side chains are prepared from tetrazoles and cyanuric chloride. The optical, nonlinear optical, and thermotropic properties of these compounds as well as their phenylethynyl homologues are reported.

    2. Metal-Free Oxidation

      One-Pot Transformation of Methylarenes into Aromatic Aldehydes under Metal-Free Conditions

      Masayuki Tabata, Katsuhiko Moriyama and Hideo Togo

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201402015

      Thumbnail image of graphical abstract

      Methylarenes were treated with DBDMH or NBS in the presence of BPO or AIBN either with heating or under irradiation conditions, followed by treatment with NMO with heating to provide the corresponding aromatic aldehydes in moderate to good yields. These reactions were carried out under transition-metal-free conditions.

    3. Natural Product Synthesis

      Synthesis and Absolute Configurations of Six Natural Phenylpropanoids

      Xue-Lian Liu, Hui-Jun Chen, Yang-Yang Yang, Yikang Wu and Jun You

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201402096

      Thumbnail image of graphical abstract

      Optically active natural products isolated many years ago with undetermined absolute configurations and simple structures unavoidably raise tantalizing questions. Do the stereogenic centres have (R) or (S) configurations? Do compounds isolated at the same time from the same plant have the same absolute configuration? Using synthesis, the answers, though somewhat unexpected, can finally be known.

    4. Asymmetric Synthesis

      (+)-Sparteine-Mediated Substitution of o-Benzyl-N-pivaloylaniline with Ketones

      Yi Kyung Ko, Chan Im, Junghwan Do and Yong Sun Park

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201402110

      Thumbnail image of graphical abstract

      The (+)-sparteine-mediated lithiation–substitution of o-benzyl-N-pivaloylaniline with various ketones afforded the corresponding tertiary alcohols and 1,4-adducts with high enantioselectivity. Moreover, this synthetic method was successfully applied to the syntheses of highly enantioenriched tetrahydroquinolines and tetralin derivatives.

  16. Short Communications

    1. Domino Reactions

      Base-Catalyzed Domino Michael–Alkyl­ation–Rearrangement Reaction: A Synthetic Route to Functionalized 2,3-Dihydrofurans

      Ren-Zun Zhang, Chang-Yu Meng, Jian-Wu Xie, Mei-Lan Xu and Wei-Dong Zhu

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201402126

      Thumbnail image of graphical abstract

      A method for the synthesis of substituted 2,3-dihydrofuran derivatives through a domino Michael–alkylation–rearrangement reaction is developed. In this transformation, broad substrate scope is demonstrated, and a plausible mechanism for this novel domino reaction is given. Ts = para-tolylsulfonyl, Lg = leaving group.

    2. Directed Organocatalysis

      Neighboring ortho-Hydroxy Group Directed Catalytic Asymmetric Triple Domino Reactions of Acetaldehyde with (E)-2-(2-Nitrovinyl)phenols

      Dhevalapally B. Ramachary, P. Srinivasa Reddy and M. Shiva Prasad

      Article first published online: 10 APR 2014 | DOI: 10.1002/ejoc.201402182

      Thumbnail image of graphical abstract

      The utilization of neighboring ortho-hydroxy group participation in the pretransition state of enamine/iminium-based triple domino Michael/aldol/oxa-Michael reactions catalyzed by (R)-DPPOTMS followed by Wittig and Michael/Wittig–Horner reactions is described. Enantiomerically pure chromanes and tetrahydro-6H-benzo[c]chromenes having three to four contiguous stereocenters are synthesized.

  17. Full Papers

    1. Synthetic Methods

      Regio-, and Stereoselective Iodobromination of Ynamides for Synthesis of (E)-1-Bromo-2-iodoenamides

      Masataka Ide, Yuta Yauchi and Tetsuo Iwasawa

      Article first published online: 9 APR 2014 | DOI: 10.1002/ejoc.201402057

      Thumbnail image of graphical abstract

      Highly regio-, and stereoselective addition reactions of IBr to ynamide were achieved by using either commercially available and/or in situ generated IBr. The method results in a single (E)-isomer product, and provides general entry to potentially diverse 1-bromo-2-iodoenamide scaffolds bearing carbamate, indole, and benzyl tosylamide.

    2. Heterocyclic Chemistry

      Sulfur–Carbon Bond Formation through Ring-Opening of Triazolothiadiazole with Organometallics

      Raja Ben Othman, Stéphane Massip, Mathieu Marchivie, Christian Jarry, Johnny Vercouillie, Sylvie Chalon, Gérald Guillaumet, Franck Suzenet and Sylvain Routier

      Article first published online: 8 APR 2014 | DOI: 10.1002/ejoc.201400151

      Thumbnail image of graphical abstract

      An efficient and convenient method was developed for the formation of S-substituted thiotriazoles through an unprecedented organometallic addition and subsequent ring-opening sequence. A wide range of substrates containing different functional groups were used, and the corresponding N-unsubstituted 3-alkyl, aryl, alkynyl and alkenyl sulfanyl-1,2,4-triazole products were produced.

    3. Mannich Condensation

      syn/anti Switching by Specific Heteroatom–Titanium Coordination in the Mannich-Like Synthesis of 2,3-Diaryl-β-amino Acid Derivatives

      Andrea Bonetti, Francesca Clerici, Francesca Foschi, Donatella Nava, Sara Pellegrino, Michele Penso, Raffaella Soave and Maria Luisa Gelmi

      Article first published online: 8 APR 2014 | DOI: 10.1002/ejoc.201400142

      Thumbnail image of graphical abstract

      A very efficient protocol for the synthesis of 2,3-diaryl-β-amino acids that uses a TiCl4/triethylamine-catalyzed Mannich-like reaction of ortho-substituted arylacetic esters or thioesters and arylimines is reported, and a high syn/anti diastereoselection is reached by variation of the ortho group. An enantioselective synthesis is also proposed.

    4. Ligand Design

      Synthesis and Selected Reactivity Studies of a Dissymmetric (Phosphinoylmethylpyridine N-Oxide) Methylamine Platform

      Sabrina Ouizem, Sylvie L. Pailloux, Alisha D. Ray, Eileen N. Duesler, Diane A. Dickie, Robert T. Paine and Benjamin P. Hay

      Article first published online: 8 APR 2014 | DOI: 10.1002/ejoc.201400120

      Thumbnail image of graphical abstract

      Syntheses for aminomethyl-functionalized (phosphorylmethyl)pyridine and -pyridine N-oxide ligands, along with reactivity studies on the appended aminomethyl site, are described. Selected lanthanide ion coordination chemistry of the pyridine N-oxide derivatives indicates how the aminomethyl group may impact the bidentate OPON chelation behavior of the parent ligand.

    5. Lithiated Allylamines

      Syntheses of Functionalized Allylamines via Lithiated Intermediates

      Samia Firdous and Uli Kazmaier

      Article first published online: 8 APR 2014 | DOI: 10.1002/ejoc.201400017

      Thumbnail image of graphical abstract

      Lithiated allylamines react with ketones and aldehydes to form aminomethylated allyl alcohols, whereas α-brominated ketones give rise to vinyl epoxides or aldehydes, depending on the reaction and workup conditions used.

    6. Natural Products

      Synthesis of Phenyl-1-benzoxepinols Isolated from Butcher's Broom and Analogous Benzoxepines

      Josef M. Herrmann, Monika Untergehrer, Guido Jürgenliemk, Jörg Heilmann and Burkhard König

      Article first published online: 8 APR 2014 | DOI: 10.1002/ejoc.201400004

      Thumbnail image of graphical abstract

      Butcher's broom extracts are used to treat inflammation. The physiological activity is mainly ascribed to steroidal saponins, but recently identified phenolic compounds, ruscozepines, may also contribute. Ruscozepine A and B and several derivatives were prepared by racemic synthesis and an ORAC–fluorescein (ORAC = oxygen radical absorbance capacity) assay revealed their antioxidative properties.

    7. Cascade Reaction

      Cascade Michael–Intramolecular Transesterification–Elimination Reaction of 3,4-Dihydro-3-nitrochromen-2-ones and β,γ-Unsaturated α-Oxo Esters: An Efficient Access to 2-Pyrone Derivatives

      Li Zhang, Youming Wang, Haibin Song, Zhenghong Zhou and Chuchi Tang

      Article first published online: 7 APR 2014 | DOI: 10.1002/ejoc.201301876

      Thumbnail image of graphical abstract

      A new base-promoted cascade Michael–intramolecular transesterification-elimination reaction of 3,4-dihydro-3-nitrochromen-2-ones and β,γ-unsaturated α-oxo esters has been developed. This process provides an efficient approach to the synthesis of multifunctionalized 2-pyrone derivatives.

  18. Short Communications

    1. Aminosulfonylation

      Palladium-Catalyzed Aminosulfonylation of Aryl Iodides by using Na2SO3 as the SO2 Source

      Wanfang Li, Haoquan Li, Peter Langer, Matthias Beller and Xiao-Feng Wu

      Article first published online: 7 APR 2014 | DOI: 10.1002/ejoc.201402212

      Thumbnail image of graphical abstract

      Gaseous sulfur dioxide is generated ex situ and employed as a cheap sulfonyl source in the palladium-catalyzed aminosulfonylation of aryl iodides. In most cases, the yields are comparable to those reported by using the 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO) as the SO2 source.

  19. Full Papers

    1. Oligosaccharide Synthesis

      One-Pot Glycosylations in the Synthesis of Human Milk Oligosaccharides

      Camilla Arboe Jennum, Thomas Hauch Fenger, Linda M. Bruun and Robert Madsen

      Article first published online: 4 APR 2014 | DOI: 10.1002/ejoc.201400164

      Thumbnail image of graphical abstract

      A one-pot glycosylation strategy has been developed for assembling the lactosamine–lactose backbone in human milk oligosaccharides, and applied in a concise synthesis of lacto-N-neofucopentaose I.

    2. Oxindole Synthesis

      Synthesis of Oxindoles through Silver-Catalyzed Trifluoromethylation–, Difluoromethylation– and Arylsulfonylation–Cyclization Reaction of N-Arylacrylamides

      Jidan Liu, Shaobo Zhuang, Qingwen Gui, Xiang Chen, Zhiyong Yang and Ze Tan

      Article first published online: 4 APR 2014 | DOI: 10.1002/ejoc.201400087

      Thumbnail image of graphical abstract

      Efficient synthesis of trifluoromethyl and difluoromethyl-substituted oxindoles was achieved by the reaction of Langlois reagent or Baran reagent with N-arylacrylamides in tBuOH/H2O by using AgNO3 as the catalyst and (NH4)2S2O8 as the oxidant. Sulfonylation could also be achieved through a similar radical procedure when Langlois reagent was replaced by arylsulfinic acid sodium salt.

    3. Pd Nanoparticles

      Heck, Sonogashira, and Hiyama Reactions Catalyzed by Palladium Nanoparticles Stabilized by Tris-Imidazolium Salt

      Marc Planellas, Yanina Moglie, Francisco Alonso, Miguel Yus, Roser Pleixats and Alexandr Shafir

      Article first published online: 4 APR 2014 | DOI: 10.1002/ejoc.201400162

      Thumbnail image of graphical abstract

      Palladium nanoparticles stabilized by a tris-imidazolium iodide act as an efficient catalyst for Heck, copper-free Sonogashira, and fluoride-free Hiyama coupling reactions. Under the developed conditions, one-pot, double Heck and Hiyama–Heck reactions have also been successfully achieved.

  20. Short Communications

    1. C–H Amidation

      Copper-Catalyzed Intramolecular Oxidative C(sp3)–H Amidation of 2-Aminoacetophenones: Efficient Synthesis of Indoline-2,3-diones

      Jinbo Huang, Tingting Mao and Qiang Zhu

      Article first published online: 3 APR 2014 | DOI: 10.1002/ejoc.201400012

      Thumbnail image of graphical abstract

      An efficient synthesis of diverse indoline-2,3-diones from 2-aminoacetophenones through copper-catalyzed intramolecular C(sp3)–H amidation is reported. The reaction proceeds in DMSO by using O2 as the sole oxidant to provide the desired products in moderate to good yields; Piv = pivaloyl.

  21. Full Papers

    1. Thermolysis

      Thermolysis of 4-Diazotetrahydrofuran-3-ones: Total Change of Reaction Course Compared to Photolysis

      Ludmila L. Rodina, Jury J. Medvedev, Olesia S. Galkina and Valerij A. Nikolaev

      Article first published online: 3 APR 2014 | DOI: 10.1002/ejoc.201400161

      Thumbnail image of graphical abstract

      Thermolysis of substituted 4-diazodihydrofuran-3-ones in aprotic media, in contrast to photolysis, gives high yields of 2,2,4,5-tetrasubstituted 3(2H)-furanones as the products of 1,2-alkyl (aryl) shifts.

    2. Cycloaddition Reactions

      1-Methyl-5-(trifluoromethyl)azafulvenium Methide, an Intermediate That Undergoes Reaction through “Unusual” cis-exo-1,3- and trans-exo-1,7-Cycloadditions

      Walter José Peláez, Ana Julieta Pepino, Gustavo Alejandro Argüello and Teresa M. V. D. Pinho e Melo

      Article first published online: 3 APR 2014 | DOI: 10.1002/ejoc.201301922

      Thumbnail image of graphical abstract

      The synthesis and reactivity of a new azafulvenium methide are described. Under microwave-induced pyrolysis conditions this intermediate could undergo an allowed suprafacial sigmatropic [1,8]H shift or be trapped by dipolarophiles, acting either as a 4π or an 8π dipole. DFT calculations showed that the major products are obtained in the trans configuration from 1,7-exo- and 1,3-endo-cycloaddition.

    3. Aminobenzofuran Approach

      Metal-Free Oxidative Cyclization of o-Acylphenols for the Construction of 2-Aminobenzofuran-3(2H)-ones

      Hui Yu, Weihua Huang and Fengling Zhang

      Article first published online: 3 APR 2014 | DOI: 10.1002/ejoc.201301756

      Thumbnail image of graphical abstract

      Oxidative coupling of 2-acylphenols with secondary amines for the preparation of 2-aminobenzofuran-3(2H)-ones is reported. Using TBHP as oxidant and I2 (or TBAI) as catalyst, various 2-aminobenzofuran-3(2H)-one derivatives were synthesized in moderate to good yields.

    4. Quaternary Amino Acids

      Asymmetric Access to α-Substituted Functional Aspartic Acid Derivatives by a [3+2] Strategy Employing a Chiral Dienophile

      Kawther Ben Ayed, Anne Beauchard, Jean-François Poisson, Sandrine Py, Mathieu Y. Laurent, Arnaud Martel, Houcine Ammar, Souhir Abid and Gilles Dujardin

      Article first published online: 2 APR 2014 | DOI: 10.1002/ejoc.201301739

      Thumbnail image of graphical abstract

      Enantiopure isoxazolidine (–)-8 is obtained through the highly diastereoselective [3+2] cycloaddition of an aspartate-derived ketonitrone and (S)-Stericol vinyl ether. Such an isoxazolidine is a direct precursor of a “superaspartic” acid bearing two differentiated side chains.

    5. Organogels

      C3-Symmetrical Cyano-Substituted Triphenylbenzenes for Organogels and Organic Nanoparticles with Controllable Fluorescence and Aggregation-Induced Emission

      Oudjaniyobi Simalou, Ran Lu, Pengchong Xue, Peng Gong and Tierui Zhang

      Article first published online: 2 APR 2014 | DOI: 10.1002/ejoc.201400014

      Thumbnail image of graphical abstract

      Three synthesized fluorescent organic molecules based on tris{2-cyano-2-[4-(dodecyloxybenzoylamino)phenyl]-1-ethenyl}phenylbenzene (CN-DBAPPBn, n = 1, 2, 3) were used to prepare organogel phases in several organic solvents, and organic nanoparticles in a mixture of THF and water. Interestingly, both phases exhibit aggregation-induced emission features.

  22. Microreviews

    1. Medicinal Heterocycle Chemistry

      1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3-Dipolar Cycloadditions

      Antonino Lauria, Riccardo Delisi, Francesco Mingoia, Alessio Terenzi, Annamaria Martorana, Giampaolo Barone and Anna Maria Almerico

      Article first published online: 31 MAR 2014 | DOI: 10.1002/ejoc.201301695

      Thumbnail image of graphical abstract

      1,3-Dipolar cycloaddition reactions, uncatalysed or catalysed by transition metals, constitute a powerful synthetic tool for 1,2,3-triazole derivatives, an important class of heterocyclic compounds in medicinal chemistry.

  23. Full Papers

    1. Protein Mimicry

      Peptidosteroid Tweezers Revisited: DNA Binding Through an Optimised Design

      Lieselot L. G. Carrette, Takashi Morii and Annemieke Madder

      Article first published online: 31 MAR 2014 | DOI: 10.1002/ejoc.201301854

      Thumbnail image of graphical abstract

      The challenging synthesis of two 25-mer peptides in parallel and in close proximity on a cholic acid moiety was optimized. The resulting peptidosteroid tweezer, a new transcription factor model, was shown to selectively bind its DNA target site.

  24. Short Communications

    1. Trifluoromethylation

      O-Trifluoromethylation of N,N-Disubstituted Hydroxylamines with Hypervalent Iodine Reagents

      Václav Matoušek, Ewa Pietrasiak, Lukas Sigrist, Barbara Czarniecki and Antonio Togni

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201402225

      Thumbnail image of graphical abstract

      Electrophilic trifluoromethylation of dialkyl hydroxylamines with hypervalent iodine(III) reagents gives access to compounds containing the virtually unexplored NOCF3 functional group. Aspects concerning synthesis, properties, and reaction mechanism are presented. The transformation is also applicable to hydroxylamines derived from common drugs and shows a broad functional group tolerance.

  25. Full Papers

    1. Cross-Coupling

      Selective Suzuki–Miyaura Monocouplings with Symmetrical Dibromoarenes and Aryl Ditriflates for the One-Pot Synthesis of Unsymmetrical Triaryls

      Corinne Minard, Carole Palacio, Kevin Cariou and Robert H. Dodd

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201400090

      Thumbnail image of graphical abstract

      By studying several key parameters, the factors that allow selective Suzuki–Miyaura monocoupling of symmetrical dihaloarenes have been outlined. This study serves as the basis for the efficient synthesis of unsymmetrical triaryls from symmetrical dibromoarenes and aryl ditriflates by a one-pot desymmetrizing double Suzuki–Miyaura coupling.

    2. Tandem Radical Reactions

      Titanocene(III) Chloride Mediated Stereoselective Synthesis of Trisubstituted Tetrahydrofurans and a Spirolactone by Tandem Radical Reactions

      Shirshendu Mukherjee, Rajdip Roy and Subhas Chandra Roy

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201400097

      Thumbnail image of graphical abstract

      The stereoselective synthesis of substituted tetrahydrofurans and a spirolactone was achieved through the reaction of a Baylis–Hillman adduct and an activated bromo/iodo compound or epoxide, respectively. This reaction occurs through a tandem radical cyclization that is mediated by titanocene(III) chloride (Cp2TiCl), which was prepared in situ from Cp2TiCl2 and zinc dust in tetrahydrofuran.

    3. Natural Product Synthesis

      Facile Formation of Methylenebis(chalcone)s through Unprecedented Methylenation Reaction. Application to Antiparasitic and Natural Product Synthesis

      Marion Thévenin, Elisabeth Mouray, Philippe Grellier and Joëlle Dubois

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201400104

      Thumbnail image of graphical abstract

      Acidic degradation of a methoxymethyl group can create a methylene bridge between two hydroxy monomeric units. This reaction affords methylenebis compounds with increased parasitic growth inhibitory activity.

    4. Hetero Cross-Coupling

      Indium(0)-Mediated C sp 3–S/O Cross-Coupling Approach Towards the Regioselective Alkylation of α-Enolic Esters/Dithioesters: A Mechanistic Insight

      Sushobhan Chowdhury, Tanmoy Chanda, Ashutosh Gupta, Suvajit Koley, B. Janaki Ramulu, Raymond C. F. Jones and Maya Shankar Singh

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201301788

      Thumbnail image of graphical abstract

      An indium(0)-mediated Cinline image–S/O cross-coupling reaction that proceeds without added co-catalyst or promoter leads to the highly regioselective alkylation of α-enolic acetate/dithioacetate systems. The selectivity for C-, S-, or O-alkylation is dependent on the nucleophilic behavior of α-enolic acetate/dithioacetate system and was further supported by DFT calculations.

    5. Direct C–H Functionalization

      Lewis-Acid-Catalyzed Benzylic Reactions of 2-Methylazaarenes with Aldehydes

      Dan Mao, Gang Hong, Shengying Wu, Xin Liu, Jianjun Yu and Limin Wang

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201400073

      Thumbnail image of graphical abstract

      Lewis-acid-promoted benzylic reactions of 2-methylazaarenes with common aldehydes have been extensively investigated for the first time. Series of azaarene derivatives including 2-(pyridin-2-yl)ethanols and 2-alkenylazaarenes were synthesized with wide substrate scopes by employing different catalysts that were optimized on the basis of the structures of the 2-methylazaarenes and the products.

  26. Short Communications

    1. Asymmetric Organocatalysis

      Regio- and Enantioselective Organocascade Michael–Michael Reactions: Construction of Chiral Trisubstituted Indanes

      Ning Li, Guo-Gui Liu, Jian Chen, Feng-Feng Pan, Bing Wu and Xing-Wang Wang

      Article first published online: 27 MAR 2014 | DOI: 10.1002/ejoc.201301860

      Thumbnail image of graphical abstract

      An organocatalytic regio- and enantioselective cascade conjugate addition reaction is developed for the construction of enantiomerically enriched 1,2,3-trisubstituted indanes. The resulting indane derivatives can be readily converted into optically active (1-indanylmethyl)amine and tetrahydroindeno[2,1-b]pyrrole derivatives. Boc = tert-butoxycarbonyl.

  27. Full Papers

    1. Reactivity

      Electrophilicities of 1,2-Disubstituted Ethylenes

      Dominik S. Allgäuer and Herbert Mayr

      Article first published online: 26 MAR 2014 | DOI: 10.1002/ejoc.201301779

      Thumbnail image of graphical abstract

      The kinetics of the reactions of 1,2-disubstituted ethylenes with pyridinium and sulfonium ylides in DMSO were investigated photometrically. From the measured second-order rate constants, along with the nucleophile-specific reactivity parameters sN and N, we were able to determine the electrophilicity parameters E of the 1,2-disubstituted ethylenes using the relationship log k2 = sN(N + E).

    2. Host–Guest Transport

      Calixarene-Mediated Liquid-Membrane Transport of Choline Conjugates

      Birendra Babu Adhikari, Ayu Fujii and Michael P. Schramm

      Article first published online: 26 MAR 2014 | DOI: 10.1002/ejoc.201400025

      Thumbnail image of graphical abstract

      Ionizable calixarenes emerge as effective transporters of choline-conjugated guests – with or without a pH gradient. A series of supramolecular calixarenes efficiently transport distinct molecular payloads through a liquid membrane when attached to a receptor-complementary handle.

  28. Short Communications

    1. Domino Reactions

      Copper-Catalyzed Domino Reaction Involving C–C Bond Cleavage To Construct 2-Aryl Quinazolinones

      Li-Xia Wang, Jun-Feng Xiang and Ya-Lin Tang

      Article first published online: 25 MAR 2014 | DOI: 10.1002/ejoc.201400108

      Thumbnail image of graphical abstract

      A copper-catalyzed approach for the synthesis of 2-aryl-quinazolinones through a domino reaction involving C–C bond cleavage is described. This transformation offers an alternative method to prepare medically important quinazolinone derivatives and a new strategy for C–C bond cleavage.

    2. Secondary Structure Mimetics

      Stereoselective Synthesis of Proline-Derived Dipeptide Scaffolds (ProM-3 and ProM-7) Rigidified in a PPII Helix Conformation

      Cédric Reuter, Margarethe Kleczka, Sarah de Mazancourt, Jörg-Martin Neudörfl, Ronald Kühne and Hans-Günther Schmalz

      Article first published online: 25 MAR 2014 | DOI: 10.1002/ejoc.201301875

      Thumbnail image of graphical abstract

      Starting from amino acid building blocks with an olefin side chain, the diastereomeric scaffolds ProM-3 and ProM-7 are synthesized through peptide coupling and ring-closing metathesis. The conformationally defined dipeptide analogs are of interest as building blocks for the synthesis of modular PPII helix secondary structure mimetics as tailored inhibitors of protein–protein interactions.

  29. Microreviews

    1. Organocatalysis

      Design Strategies for Enhanced Hydrogen-Bond Donor Catalysts

      Tyler J. Auvil, Andrew G. Schafer and Anita E. Mattson

      Article first published online: 21 MAR 2014 | DOI: 10.1002/ejoc.201400035

      Thumbnail image of graphical abstract

      Since initial reports of organocatalysis through hydrogen bonding interactions, a number of strategies have emerged to allow access to enhanced hydrogen-bond donor (HBD) organocatalysts. These strategies range from augmentation of existing HBDs to the design and synthesis of new HBD catalysts. The effects of recent dual HBD designs on catalyst performance are described.

  30. Full Papers

    1. Heterocyclic Chemistry

      A High Yield Procedure for the Preparation of 2-Hydroxynitrostyrenes: Synthesis of Imines and Tetracyclic 1,3-Benzoxazines

      Víctor Tena Pérez, Ángel L. Fuentes de Arriba, Laura M. Monleón, Luis Simón, Omayra H. Rubio, Francisca Sanz and Joaquín R. Morán

      Article first published online: 21 MAR 2014 | DOI: 10.1002/ejoc.201402016

      Thumbnail image of graphical abstract

      The reaction of salicylaldehyde, nitromethane, and ammonium acetate yields a surprisingly stable imine, which hinders the synthesis of 2-hydroxynitrostyrene. Herein, we present a procedure to overcome this drawback and report the reaction of this stable imine with phosgene to afford benzoxazines in good yields.

  31. Short Communications

    1. Trifluoromethylthiolation

      Trifluoromethylthiolation of Diazo Compounds through Copper Carbene Migratory Insertion

      Xi Wang, Yujing Zhou, Guojing Ji, Guojiao Wu, Ming Li, Yan Zhang and Jianbo Wang

      Article first published online: 18 MAR 2014 | DOI: 10.1002/ejoc.201402105

      Thumbnail image of graphical abstract

      A strategy to introduce the SCF3 group through the CuI-promoted reaction of diazo compounds with the nucleophilic AgSCF3 trifluoromethylthiolation reagent is developed. Various diazo compounds are smoothly converted under mild conditions to form the C(sp3)–SCF3 bond. Migratory insertion of SCF3-bearing CuI carbene intermediates is proposed as the key step in this transformation.

  32. Microreviews

    1. Alkyne Hydrothiolation

      Metal-Catalyzed and Metal-Free Alkyne Hydrothiolation: Synthetic Aspects and Application Trends

      Alessandro Dondoni and Alberto Marra

      Article first published online: 18 MAR 2014 | DOI: 10.1002/ejoc.201301879

      Thumbnail image of graphical abstract

      Metal-catalyzed approaches for the selective preparation of vinyl thioethers (top) and free-radical approaches for the assembly of multifunctionalized constructions (bottom) are surveyed.

  33. Full Papers

    1. Kinetic Resolution

      Dynamic Double Kinetic Resolution of Amines and Alcohols under the Cocatalysis of Raney Nickel/Candida antarctica Lipase B: From Concept to Application

      Bo Xia, Guilin Cheng, Xianfu Lin and Qi Wu

      Article first published online: 18 MAR 2014 | DOI: 10.1002/ejoc.201400042

      Thumbnail image of graphical abstract

      A dynamic double kinetic resolution (DDKR) strategy under the co-catalysis of Raney nickel and Candida antarctica lipase B (CAL-B) was established for the one-pot simultaneous resolution of primary amines and secondary alcohols.

    2. Thiazole Synthesis

      Synthesis of Unexpected Bifunctionalized Thiazoles by Nucleophilic Attack on Allenyl Isothiocyanate

      Baker Jawabrah Al-Hourani, Frank Richter, Kai Vrobel, Klaus Banert, Marcus Korb, Tobias Rüffer, Bernhard Walfort and Heinrich Lang

      Article first published online: 18 MAR 2014 | DOI: 10.1002/ejoc.201301851

      Thumbnail image of graphical abstract

      Treatment of allenyl isothiocyanate with hydroxylamines led to 5-aminomethylthiazol-2(3H)-ones. O-Amino N-allenylthiocarbamates could be detected as intermediates. Thus, an addition–cyclization–cleavage–addition mechanism via the short-lived 5-methylidenethiazol-2(5H)-one is proposed. The reaction of the isothiocyanate with azide salt or hydrazoic acid gave comparable results.

  34. Short Communications

    1. Hydration Reactions

      Gold(I)-Catalyzed Hydration of Alkynylphosphonates: Efficient Access to β-Ketophosphonates

      Longyong Xie, Rui Yuan, Ruijia Wang, Zhihong Peng, Jiannan Xiang and Weimin He

      Article first published online: 17 MAR 2014 | DOI: 10.1002/ejoc.201400066

      Thumbnail image of graphical abstract

      An efficient and mild gold-catalyzed hydration process for the regioselective synthesis of β-ketophosphonates directly from alkynylphosphonates is described. Twenty-two examples with yields of 85–97 % are reported. Different substituents including substituted aryl, alkyl, chloro, ester, sulfonoxyl, and phthalimide groups are tolerated; XPhos = 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl, Tf = trifluoromethylsulfonyl.

    2. Halocyclization

      Efficient Synthesis of Dihydropyrazoles by Halocyclization of β,γ-Unsaturated Hydrazones

      Xiao-Qiang Hu, Jia-Rong Chen, Qiang Wei, Feng-Lei Liu, Qiao-Hui Deng, You-Quan Zou and Wen-Jing Xiao

      Article first published online: 17 MAR 2014 | DOI: 10.1002/ejoc.201402021

      Thumbnail image of graphical abstract

      The halocyclization of β,γ-unsaturated hydrazones and N-bromosuccinimide without the addition of any additives under mild reaction conditions provides facile access to biologically important 4,5-dihydropyrazoles. A variety of highly substituted 4,5-dihydropyrazoles are prepared in good to excellent yields. This reaction also provides access to pyrazoles in a one-pot fashion. Ts = p-tolylsulfonyl.

  35. Full Papers

    1. Free Radical Rearrangements

      Flash Vacuum Thermolysis of N-(3- and 4-Pyridylmethylidene)-tert-butylamines: Mechanisms of Formation of Pyrrolopyridines and Naphthyridines

      Katarzyna Justyna, Stanisław Leśniak, Ryszard B. Nazarski, Michał Rachwalski, Thien Y. Vu, Thi Kieu Xuan Huynh, Saïd Khayar, Alain Dargelos, Anna Chrostowska and Curt Wentrup

      Article first published online: 17 MAR 2014 | DOI: 10.1002/ejoc.201400112

      Thumbnail image of graphical abstract

      Free radicals generated by flash vacuum thermolysis of N-tert-butylpyridylmethylideneimines rearrange to pyrrolopyridines and naphthyridines The reaction mechanisms, supported by calculations at the CAM-B3LYP/6-311G(d,p) level indicate that the reactions take place through hitherto little-known 2- and 1-azaallyl and aziridinyl radicals

    2. Indole Alkaloid Synthesis

      Total Synthesis of Quebrachamine through Macrolactamization

      Shih-Wen Hsu, Hsiu-Yi Cheng, An-Chi Huang, Tse-Lok Ho and Duen-Ren Hou

      Article first published online: 17 MAR 2014 | DOI: 10.1002/ejoc.201400064

      Thumbnail image of graphical abstract

      Quebrachamine was efficiently prepared from macrolactamization of 17, which was prepared through Sonogashira coupling and cis-hydrogenation.

    3. Dehydrogenation

      IBX-Mediated Dehydrogenation of Substituted β-Oxonitriles

      Philipp Klahn and Stefan F. Kirsch

      Article first published online: 17 MAR 2014 | DOI: 10.1002/ejoc.201402007

      Thumbnail image of graphical abstract

      By the action of IBX, β-oxonitriles undergo dehydrogenation to the unsaturated compounds at room temperature. The dehydrogenation can be coupled with a hetero-Diels–Alder reaction to provide a new method for the synthesis of dihydropyrans. Moreover, the dehydrogenation of cyclic β-oxonitriles can be used for the synthesis of substituted phenols.

  36. Short Communications

    1. Vinylogous Peptides

      Synthesis of Enaminone-Based Vinylogous Peptides

      Luka Šenica, Uroš Grošelj, Marta Kasunič, Drago Kočar, Branko Stanovnik and Jurij Svete

      Article first published online: 13 MAR 2014 | DOI: 10.1002/ejoc.201402033

      Thumbnail image of graphical abstract

      Vinylogous peptides with a C=C fragment inserted into a peptide C–N bond are prepared from ynone building blocks that are easily available from Boc-protected α-amino acids. Coupling at the C terminus is achieved by 1,4-addition of an α-amino ester, whereas coupling at the N terminus requires temporary protection of the enaminone moiety by transformation into an isoxazole derivative.

    2. Spiroisoxazoline Derivatives

      A Model Study toward the Concise Synthesis of Bromotyrosine-Derived Spiroisoxazoline Natural Products and Analogous Core Structures

      Prasanta Das, Edward J. Valente and Ashton T. Hamme II

      Article first published online: 13 MAR 2014 | DOI: 10.1002/ejoc.201400009

      Thumbnail image of graphical abstract

      The efficient syntheses of functionalized spiroisoxazolines that closely resemble bromotyrosine-derived spiroisoxazoline natural product core structures are described. This described strategy could serve as an efficient alternative to previously developed approaches that involve aromatic ring oxidation as the essential step to synthesize this class of natural products.

    3. Ring Opening of Cyclopropenone

      Phosphane- and Amine-Catalyzed Ring-Opening Reactions of Cyclopropenones with Isatin Derivatives: Synthesis of Carboxylated 1H-Indoles and Multisubstituted 2H-Pyran-2-ones

      Wen-Tao Zhao, Xiang-Ying Tang and Min Shi

      Article first published online: 12 MAR 2014 | DOI: 10.1002/ejoc.201400077

      Thumbnail image of graphical abstract

      Phosphane- and amine-catalyzed ring-opening reactions of cyclopropenones with isatin derivatives are developed. These reactions offer a facile synthetic method to construct carboxylated 1H-indoles and multisubstituted 2H-pyran-2-ones; Boc = tert-butoxycarbonyl, DABCO = 1,4-diazabicyclo[2.2.2]octane.

  37. Full Papers

    1. Nitrogen Heterocycles

      Iron(III)-Catalyzed Denitration Reaction: One-Pot Three-Component Synthesis of Imidazo[1,2-a]pyridine Derivatives

      Hao Yan, Yuling Wang, Congming Pan, Hao Zhang, Sizhuo Yang, Xiaoyu Ren, Jian Li and Guosheng Huang

      Article first published online: 11 MAR 2014 | DOI: 10.1002/ejoc.201301658

      Thumbnail image of graphical abstract

      An iron(III)-catalyzed one-pot three-component cross-coupling nitration reaction of 2-aminopyridines, aldehydes, and nitroalkane, leading to the straightforward formation of imidazo[1,2-a]pyridine derivatives has been reported. In this procedure, the starting materials are commercially available. The system shows good functional-group tolerance and proceeds smoothly in moderate to good yields.

    2. Tröger's Bases

      Synthesis of Unsymmetrical Tröger's Bases Bearing Groups Sensitive to Reduction

      Martin Havlík, Bohumil Dolenský, Milan Jakubek and Vladimír Král

      Article first published online: 10 MAR 2014 | DOI: 10.1002/ejoc.201301517

      Thumbnail image of graphical abstract

      We report an efficient synthetic protocol for the preparation of Tröger's base derivatives bearing functional groups sensitive to reduction conditions. Twelve unsymmetrical derivatives were prepared in high overall yields using this protocol.

    3. Nickel Catalysis

      Efficient C–N and C–S Bond Formation Using the Highly Active [Ni(allyl)Cl(IPr*OMe)] Precatalyst

      Anthony R. Martin, David J. Nelson, Sébastien Meiries, Alexandra M. Z. Slawin and Steven P. Nolan

      Article first published online: 7 MAR 2014 | DOI: 10.1002/ejoc.201402022

      Thumbnail image of graphical abstract

      In the Nick of time: Two [Ni(allyl)Cl(NHC)] complexes with the bulky yet flexible N-heterocyclic carbene (NHC) ligands IPr* and IPr*OMe are reported. An assessment of the catalytic performance of these complexes in Buchwald–Hartwig and thiophenol arylation reactions is described, with the precatalyst [Ni(allyl)Cl(IPr*OMe)] exhibiting outstanding activity.

  38. Short Communications

    1. Supramolecular Chemistry

      Fluorescence Enhancement of a Porphyrin–Viologen Dyad by Pseudorotaxane Formation with Cucurbit[7]uril

      Maher Fathalla, Nathan L. Strutt, Jonathan C. Barnes, Charlotte L. Stern, Chenfeng Ke and J. Fraser Stoddart

      Article first published online: 7 MAR 2014 | DOI: 10.1002/ejoc.201402018

      Thumbnail image of graphical abstract

      The electron-transfer processes within a donor–acceptor dyad can be readily controlled through the formation of a pseudorotaxane between a viologen acceptor and cucurbit[7]uril.

  39. Full Papers

    1. Trisubstituted 2,5-Diketopiperazines

      Asymmetric Synthesis of 3,4,6-Trisubstituted 2,5-Diketopiperazines by Using Dynamic Kinetic Resolution of α-Bromo Tertiary Acetamides

      Jinho Baek, Seock Yong Kang, Chan Im and Yong Sun Park

      Article first published online: 6 MAR 2014 | DOI: 10.1002/ejoc.201301936

      Thumbnail image of graphical abstract

      A new asymmetric synthetic route to 3,4,6-trisubstituted 2,5-diketopiperazines has been developed by using a nucleophilic substitution reaction of L-amino-acid-derived α-bromo tertiary acetamides with p-anisidine followed by a deprotection–cyclization process.

    2. Nucleoside Analogues

      Synthesis of Purine Nucleosides from D-Glucuronic Acid Derivatives and Evaluation of Their Cholinesterase-Inhibitory Activities

      Nuno M. Xavier, Stefan Schwarz, Pedro D. Vaz, René Csuk and Amélia P. Rauter

      Article first published online: 6 MAR 2014 | DOI: 10.1002/ejoc.201301913

      Thumbnail image of graphical abstract

      The synthesis of furanosyl and pyranosyl N9 and N7 purine nucleosides containing glucofuranurono-6,3-lactone, N-benzylglucuronamide, and glucuronic acid moieties is reported. Glucuronolactones were used as glycosyl donors or converted into suitable 1-O-acetyl derivatives for purine glycosylation. Some nucleosides showed moderate and selective inhibition of acetylcholinesterase.

    3. Helical Organocatalysts

      Synthesis, Characterisation, and Organocatalytic Activity of Chiral Tetrathiahelicene Diphosphine Oxides

      Silvia Cauteruccio, Davide Dova, Maurizio Benaglia, Andrea Genoni, Manuel Orlandi and Emanuela Licandro

      Article first published online: 6 MAR 2014 | DOI: 10.1002/ejoc.201301912

      Thumbnail image of graphical abstract

      A novel class of tetrathia[7]helicene-based diphosphine oxides has been synthesised, and their catalytic behaviour as chiral helical phosphorus Lewis bases has been preliminary investigated in organocatalytic reactions.

    4. Triplet Aromaticity

      Evaluation of Triplet Aromaticity by the Indene–Isoindene Isomerization Stabilization Energy Method

      Ke An and Jun Zhu

      Article first published online: 5 MAR 2014 | DOI: 10.1002/ejoc.201301810

      Thumbnail image of graphical abstract

      Triplet aromaticity has been evaluated by applying the indene–isoindene isomerization stabilization energy (ISE) method. The reliability of this approach can be demonstrated by the strong correlation of ISE values with NICS(1)zz as well as the previous methyl–methylene ISE values. Our results verify Baird's rule: that triplet annulenes with 4n π-electrons are aromatic.

    5. C–H Activation

      A Commercially Available Tantalum Catalyst for the Highly Regioselective Intermolecular Hydroaminoalkylation of Styrenes

      Jaika Dörfler and Sven Doye

      Article first published online: 4 MAR 2014 | DOI: 10.1002/ejoc.201400082

      Thumbnail image of graphical abstract

      Highly regioselective intermolecular hydroaminoalkylation reactions of styrenes are achieved in the presence of the commercially available homoleptic catalyst [Ta(NMe2)5]. The process activates the α-C–H bonds of N-methylanilines and 1,2,3,4-tetrahydroquinoline and gives access to the corresponding branched hydroaminoalkylation products in good-to-excellent yields.

    6. C–H Functionalization/Cyclization

      Copper- and Palladium-Cocatalyzed Intramolecular C–H Functionalization/C–N Bond Formation: A Route to the Synthesis of Indoloisoquinoline Derivatives

      Somjit Hazra, Biplab Mondal, Habibur Rahaman and Brindaban Roy

      Article first published online: 28 FEB 2014 | DOI: 10.1002/ejoc.201301699

      Thumbnail image of graphical abstract

      A new approach to the synthesis of indoloisoquinoline derivatives is described. The activation of the indole C2–H bond is accomplished here by using a Pd(OAc)2 and Cu(OTf)2 bi-catalytic system. In this reaction aldoximes are converted into the corresponding isoquinolines in open atmosphere under mild reaction condition.

    7. Orthophosphate Recognition

      Guanidinium-Based Artificial Receptors for Binding Orthophosphate in Aqueous Solution

      Evgeny A. Kataev, Christoph Müller, Grigory V. Kolesnikov and Victor N. Khrustalev

      Article first published online: 27 FEB 2014 | DOI: 10.1002/ejoc.201301867

      Thumbnail image of graphical abstract

      Selective recognition of orthophosphate in aqueous solution was achieved by receptors based on guanidinium and pyrrole binding sites. The structure of pyrrole-containing binding sites has great influence on the selectivity of receptors for orthophosphate. The receptor with bulky substituents in the meso-position of the dipyrrolylmethane core demonstrated the highest selectivity for orthophosphate

    8. Tunable Anion Binding

      Synthesis of 1,2,3-Triazole-4-carboxamide-Containing Foldamers for Sulfate Recognition

      Li Cao, Runsheng Jiang, Yulan Zhu, Xinlong Wang, Yongjun Li and Yuliang Li

      Article first published online: 27 FEB 2014 | DOI: 10.1002/ejoc.201301838

      Thumbnail image of graphical abstract

      A series of triazolecarboxamide-containing foldamers were synthesized. By increasing the numbers of triazolecarboxamide units and modification of the terminal benzene ring, the binding stoichiometry and binding affinity can be controlled.

    9. Peptidomimetics

      Structural Prerequisites for Receptor Binding of Helicokinin I, a Diuretic Insect Neuropeptide from Helicoverpa zea

      Chien Tran Van, Tino Zdobinsky, Guiscard Seebohm, Dirk Nennstiel, Oliver Zerbe and Jürgen Scherkenbeck

      Article first published online: 26 FEB 2014 | DOI: 10.1002/ejoc.201301773

      Thumbnail image of graphical abstract

      A delicate balance of rigidity and flexibility makes the difference between activity and inactivity. Detailed conformational studies of analogues of the diuretic insect-neuropeptide helicokinin I containing diverse cyclic scaffolds with different flexibility and orientation of the N- and C-termini provide a better understanding of the structural requirements for receptor binding.

    10. [4+3] Cycloaddition

      Use of the p-Tolylsulfinyl Group as a Chiral Inductor in Stereoselective [4+3] Cycloaddition Reactions: Preparation of Enantiopure Polysubstituted 8-Oxabicyclo[3.2.1]oct-6-en-3-one Systems Having up to Five Stereocenters

      Ángel M. Montaña, Pedro M. Grima, Consuelo Batalla, Francisca Sanz and Gabriele Kociok-Köhn

      Article first published online: 25 FEB 2014 | DOI: 10.1002/ejoc.201301814

      Thumbnail image of graphical abstract

      The use of the p-tolylsulfinyl group as a chiral inductor in stereoselective [4+3] cycloadditions has led to the preparation of enantiopure polysubstituted 8-oxabicyclo[3.2.1]oct-6-en-3-ones with up to five stereocenters in yields of 50–80 %. By using appropriate substituents on the furan ring, 100:0 cis-trans, 100:0 endo-exo, and up to 100 % π-facial diastereoselectivities were achieved.

  40. Corrections

    1. You have free access to this content
      Enantioselective Squaramide-Catalysed Domino Mannich–Cyclization Reaction of Isatin Imines

      Xi-Bo Wang, Tian-Ze Li, Feng Sha and Xin-Yan Wu

      Article first published online: 24 FEB 2014 | DOI: 10.1002/ejoc.201402056

      This article corrects:

      Enantioselective Squaramide-Catalysed Domino Mannich–Cyclization Reaction of Isatin Imines

      Vol. 2014, Issue 4, 739–744, Article first published online: 21 NOV 2013

  41. Full Papers

    1. Enzyme Catalysis

      A One-Pot Oxidation/Enantioselective Oxa-Michael Cascade

      Jorgen S. Willemsen, Rik P. Megens, Gerard Roelfes, Jan C. M. van Hest and Floris P. J. T. Rutjes

      Article first published online: 24 FEB 2014 | DOI: 10.1002/ejoc.201301885

      Thumbnail image of graphical abstract

      A one-pot reaction was developed containing a laccase/(2,2,6,6-tetramethylpiperidin-1-yl)oxy-mediated oxidation followed by a DNA-based, copper-catalysed oxa-Michael addition reaction. The enantioselective oxa-Michael addition reaction only occurred if the sequence was performed stepwise and the first reaction was inhibited with HCO2K.

  42. Microreviews

    1. Enantioselective Ketone Reduction

      Baker's-Yeast-Mediated Reduction of Sulfur-Containing Compounds

      Rebecca E. Deasy and Anita R. Maguire

      Article first published online: 24 FEB 2014 | DOI: 10.1002/ejoc.201301729

      Thumbnail image of graphical abstract

      Stereochemical control in the baker's yeast reduction of ketones through the introduction of sulfur functional groups (sulfides, sulfoxides and sulfones) or sulfur-containing additives has attracted considerable attention. This microreview provides a summary of developments to date, highlighting the synthetic utility of the yeast-mediated ketone reduction influenced by the presence of sulfur moieties.

  43. Full Papers

    1. Non-natural Peptides

      δ-Peptides from RuAAC-Derived 1,5-Disubstituted Triazole Units

      Johan R. Johansson, Elin Hermansson, Bengt Nordén, Nina Kann and Tamás Beke-Somfai

      Article first published online: 14 FEB 2014 | DOI: 10.1002/ejoc.201400018

      Thumbnail image of graphical abstract

      A new set of non-natural peptides composed of 1,5-disubstituted 1,2,3-triazole amino acids is presented. These peptides benefit from: a) modular synthesis of the monomers, allowing variation of the side chains; b) increased solubility of the oligomers in water, irrespective of peptide length; c) flexibility of the backbone allowing these foldamers to adopt several conformations.

  44. Microreviews

    1. Catalytic Asymmetric Lactonization

      Asymmetric Iodolactonization: An Evolutionary Account

      Jens M. J. Nolsøe and Trond V. Hansen

      Article first published online: 11 FEB 2014 | DOI: 10.1002/ejoc.201301400

      Thumbnail image of graphical abstract

      Iodolactonization is a valuable synthetic tool owing to the inherent stereochemical nature of the process. From a substrate perspective, the asymmetric reaction has been pursued with great zeal. In contrast, moving beyond the chiral environment offered by the prospective ring has long been neglected. However, in the last three years several highly enantioselective catalytic protocols have emerged.

    2. β-Lactams

      Progress in Asymmetric Organocatalytic Synthesis of β-Lactams

      Plato A. Magriotis

      Article first published online: 28 JAN 2014 | DOI: 10.1002/ejoc.201301720

      Thumbnail image of graphical abstract

      The importance of β-lactams and asymmetric organocatalysis is first discussed, followed by the initial asymmetric syntheses of β-lactams with the aid of chirally modified transition-metal catalysts. Progress in organocatalyzed enantioselective Staudinger syntheses of β-lactams since 2001, including kinetic resolution of β-lactams and indirect asymmetric syntheses of β-lactams, is then reviewed.

    3. Johnson–Claisen Rearrangement

      The Orthoester Johnson–Claisen Rearrangement in the Synthesis of Bioactive Molecules, Natural Products, and Synthetic Intermediates – Recent Advances

      Rodney A. Fernandes, Asim K. Chowdhury and Pullaiah Kattanguru

      Article first published online: 29 OCT 2013 | DOI: 10.1002/ejoc.201301033

      Thumbnail image of graphical abstract

      The orthoester Johnson–Claisen rearrangement is a one-pot, one-step process for C–C bond formation. This review covers developments in the orthoester Johnson–Claisen rearrangement since 2003. The applications of this rearrangement in the synthesis of bioactive molecules, natural products, analogues, synthetic intermediates, and building blocks are covered.

VIEW

  1. 1 - 100

SEARCH

SEARCH BY CITATION